Metallurgy of Ancient Indian Iron and steel:
orge-welded iron cannons of India
According to Bala, the forge welded cannons truly represent the mastery of iron ore mining, extraction and manufacturing technology of Indian blacksmiths. As opposed to cast iron cannon technology developed in Europe, Indians practiced forge welding technology and produced large cannons from direct reduced wrought iron. Bala has described in detail the technology as well as the history of some of the most massive forge-welded iron cannons in the world which are scattered all over the Indian subcontinent– Thanjavur, Dhaka, Murshidabad, Bishnupur, Jhansi, Assam, Tripura, Gulbarga, Bijapur, Bidar, Golconda, Hyderabad, and many Deccan forts.
The cannon technology was a crucial element in the rise and fall of several dynasties in India such as the Mughals, Marathas, Sikhs and Rajputs. It is certain that the latest technologies prevalent in Europe were also known to Indians. For example when the British defeated Tipu Sultan in 1799, they were astonished by the quality of his cannon.
Nine hundred and twenty seven cannon were captured after the fall of Srirangapatnam in 1799.
European colonizers used superior cast iron cannons and also systematically destroyed the forge-welded cannons from the Indian forts, according to Bala.
Agarias, a tribe in Madhya Pradesh, are traditional iron smelters
A 17th century forge-welded iron cannon, at Thanjavur’s eastern entrance (India).
The Jaivana cannon is the largest wheeled cannon ever constructed. It is located at the Jaigarh Fort, Jaipur. It was cast in 1720, during the reign of Maharaja Sawai Jai Singh II of Jaipur. The formidable strength of its builder, the scientifically inclined warrior Sawai Jai Singh II, lay in the large number of artillery and copious supply of munitions which he maintained. Jaivan rests on a high 4 wheeled carriage. The front wheels are 2.74 m in diameter and the rear wheels are 1.37 m in diameter.
The length of the barrel of the cannon is 20 feet 2 inches and it weighs 50 tons.
Wootz Steel
One of the greatest technological achievements to originate from the Indian subcontinent is Deccan Wootz Steel, often referred to as “the wonder material of the orient”.
The world famous Damascus swords were made of Wootz steel and these were considered to be the most prized possessions and gift items (certainly more precious than gold and silver) by the aristocracy. There is no evidence to show that any of the nations of antiquity besides the Indians were acquainted with the art of making steel. The word Wootz is a distortion of the Kannada-Telugu word Ukku, for steel.
Wootz Steel as the Acme of Mankind’s Metallurgical Heritage
“Wootz was the first high-quality steel
made anywhere in the world. According
to reports of travelers to the East,
the Damascus swords were made
by forging small cakes of steel that
were manufactured in Southern India.
This steel was called wootz steel.
It was more than a thousand years before
steel as good was made in the West.”
What is Wootz? Its Place in the History of Technology
The school or college going student today may not be aware that India’s contributions
and prowess in the making of iron and steel were amongst the most remarkable in the
ancient world. Of course, many of them may have had the occasion on school tours to
visit the imposing Qutb Minar Complex in New Delhi and to admire the splendid Gupta
era Iron Pillar (ca 400-420 AD). It stands as a monument to a glorious Indian tradition in
the field of ferrous metallurgy. The Iron Pillar, the earliest and the largest surviving iron
forging in the world, is regarded as a metallurgical marvel because it has defied the laws
of corrosion of iron even after so many centuries, earning the nickname, the ‘rustless
wonder’. However, the Iron Pillar is not the only testimony that there is to the skills of
ancient Indian iron and steel metallurgy.
There is another truly remarkable story that is not so well known. This is the chronicle of
the legendary wootz steel from India, which has long been a subject of much fascination
around the globe, with many legends and accounts surrounding it. This book highlights
the fact that India led the world in developing an impressive tradition more than two
milennia ago of making high-grade steel in South India, known as wootz.
But what is this strange word, wootz? The term was coined, when European travellers
from the 17th century onwards came across the making of steel by crucible processes in
Southern India in the present day states of Tamil Nadu, Andhra Pradesh and Karnataka.
Wootz was the anglicization of ‘ukku’, the Kannada word for steel.
The fame of steel from India is well captured in the words of the Arab Edrisi (12th
century) who commented that:
‘the Hindus excelled in the manufacture of iron and it is impossible to find anything to
surpass the edge from Hinduwani or Indian steel’
Zinc:
The earliest firm evidence for the production of metallic zinc comes from India. Of the
eight metals used in antiquity zinc is one of the most difficult to smelt since it volatalises
at about the same temperature of around 1000 ºC that is needed to smelt zinc ore. As a
result, it forms as a vapour in the furnace which would immediately get reoxidised and
hence lost. So there are very few references to metallic zinc in early treatises. In India
there is unique evidence for the extensive and semi-industrial production of zinc at the
Zawar area of Rajasthan. An ingenious method was devised of downward distillation of
the zinc vapour formed after smelting zinc ore using specifically designed retorts with
condensers and furnaces. The zinc vapour could be drastically cooled down to get a melt
that could solidify to zinc metal. The Rasaratnakara, a text ascribed to the great Indian
scientist Nagarjuna, of the early Christian era describes this method of production of zinc.
In Europe, the production of metallic zinc was virtually unknown until William
Champion first established commercial zinc smelting operations in Bristol in the 1740's
following which it was industrially produced. Interestingly, the method of production
adopted by downward distillation bears a strong resemblance to the Zawar process. It has
been pointed out that Champion's process was very likely inspired by the Zawar process
which would have been made known to the British during the forays of the East India
Company.
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